RU2342570C1 - Block of screwed joint - Google Patents

Abstract

FIELD: machine construction.

SUBSTANCE: invention relates to responsible units used in machine construction and which work in conditions of complex loading. The connection unit of machine components contains two connectable parts, bolt and nuts. In the first connectable part a split conical plug is mounted without any gaps with a metal to metal fit with a bolt. In the second connectable part with a gap is placed cylindrical bushing with the inner conical bolt for putting the conical part of the stud-bolt tightly.

EFFECT: strengthening the joint, equal distribution of transversal load in sectional bolt joints, increase in working capacity of the unit when displaced.

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Description

The invention relates to critical nodes used in mechanical engineering and operating under complex loading conditions.

Known nodes of the connection of machine parts in which the connection is made with bolts installed in the holes without a gap [1] (p. 36 of FIG. 1.20).

In the joint assembly in which the bolts are installed in the hole without clearance, the parts to be joined must be jointly processed. Moreover, the holes in the connected parts are calibrated by reaming or bored together with great accuracy, and the diameter of the bolt rod is performed with a tolerance that provides a given fit.

These technological operations are very time-consuming, especially for large-sized parts, often manufactured in different cities. The assembly and disassembly of such joints leads to seizure of the seating surfaces of the holes of the parts and the polished surfaces of the bolts, which significantly reduces the accuracy of the regulated fit of the joints and as a result reduces the uniform distribution of the transverse load.

There is also a knot for connecting machine parts, in which the bolt is delivered without a gap in the part to which the nut is adjacent, and the bolt is delivered with a calculated gap in another part [2].

The main disadvantage of this solution is the need to ensure a sufficiently high accuracy of alignment of the holes of the parts to be joined, which is also difficult in a unit with a group threaded connection.

The purpose of the invention is to increase the strength of the connection by significantly reducing the bending stress under the threaded part, increasing the uniformity of the distribution of the transverse load in the group threaded connection, therefore, increasing the efficiency of the node in shear.

This goal is achieved by the fact that in the first connected part, a split conical sleeve for landing without a stud gap is installed without a gap, in the second connected part with a gap, a cylindrical sleeve with an inner conical hole for fitting the conical part of the stud with an interference fit is installed.

The invention is illustrated in the drawing.

The assembly contains parts 1 and 2, a stud 3, a tapered split sleeve 4, a cylindrical sleeve 5, nuts 6 and 7.

In detail 1, a cylindrical hole with a diameter of d _{1 is made} , in which a cylindrical sleeve with a diameter of d ₄ with an internal conical hole, diameters d ₂ and d _{5 is} installed with a gap to fit the conical part of the stud 3 with diameters d ₃ and d ₅ with an interference fit.

In detail 2, a conical hole with diameters d ₆ and d _{8 is made} , in which a conical split sleeve 4 with diameters d ₇ and d _{8 is} installed for the stud 3 to be fitted with an interference fit in section l ₇ .

On the side of the nut 7, when assembling the connection, the stud 3 freely passes through the hole d _{6 of the} part 1 and enters with a gap into the hole of the split conical sleeve 4. Then, the cylindrical sleeve 5 is installed and the nut 7 is pre-tensioned, which provides a preload in the connection of the cylindrical sleeve-stud. Next, the nut 6 is tightened for a given force, which provides an interference fit in the connection of the split sleeve-stud due to the choice of the gap of the split cone.

When a group threaded joint is operated under transverse loads, all fasteners are deformed as rods with two pinched edges. The pin jamming in the section, which coincides with the supporting surface of the nut 7, is ensured by creating an interference fit in the pair of the cylindrical sleeve-pin, and in item 2, pinching of the bolt is ensured by landing without a gap in the split sleeve 4, which is clamped in this part by tightening the nut. As a result, a rigid assembly is formed: part 2 - sleeve 4 - part 1 - sleeve 5, which moves when loading the connection as one solid body.

As a result of all this, the uniformity of loading of all the bolts of the group threaded joint receiving the shear force is significantly increased, and the overall bearing capacity of the joint is also increased.

The use of the proposed connection node is especially effective in expensive power machines that transmit significant loads.

INFORMATION SOURCES

1. Ivanov M.N., Finagenov V.A. Machine parts. M .: "Higher School", 2002, p.407.

2. Patent No. 2169876. Moscow, 06.27.2001 (prototype). Authors: Bugov X.U., Egorzhev AM, Semenov L.Kh. and etc.

Claims (1)

A node for connecting machine parts, comprising two connected parts, a stud with nuts, characterized in that a split conical sleeve is fitted without clearance in the first joined part without a stud clearance, and a cylindrical sleeve with an inner conical hole for tapered fitting is installed in the second connected part with a gap interference stud parts.